This paper sheds some new light on the multivariate (projectional) quantiles recently introduced in Kong and Mizera (2008). Contrary to the sophisticated set analysis used there, we adopt a more parametric approach and study the subgradient conditions associated with these quantiles. In this setup, we introduce Lagrange multipliers which can be interpreted in various interesting ways. We also l...

Today’s challenges for language development include language extension and composition, as well as the use of diverse notations. A promising approach is projectional editing, a technique to directly manipulate the abstract syntax tree of a program, without relying on parsers. Its potential lies in the ability to combine diverse notational styles – such as text, symbols, tables, and graphics – a...

Tool support for language engineering has typically prioritises concrete syntax over abstract syntax by providing meta-languages for expressing concrete syntax and then mapping concrete to abstract structures. Text-based languages are usually specified using a BNF-like language used to generate a syntax-aware editor that includes features such as keyword completion. Similarly, graphical languag...

Any higher dimensional shift space (X, d) contains many lower dimensional shift spaces obtained by projection onto r-dimensional sublattices L of d where r < d. We show here that any projectional entropy is bounded below by the d entropy and, in the case of certain shifts of finite type satisfying a mixing condition, equality is achieved if and only if the shift of finite type is the infinite p...

Domain-specific languages (DSLs) are of increasing importance in scientific high-performance computing to reduce development costs, raise the level of abstraction and, thus, ease scientific programming. However, designing DSLs is not easy, as it requires knowledge of the application domain and experience in language engineering and compilers. Consequently, many DSLs follow a weak approach using...

This paper describes a novel approach to embedded software development. Instead of using a combination of C code and modeling tools, we propose an approach where modeling and programming is unified using projectional language workbenches. These allow the incremental, domainspecific extension of C and a seamless integration between the various concerns of an embedded system. The paper does not p...